Enter values and select Calculate.
Calculated result
Calculation steps
Formula and worked example
Percentage increase = (new − original) ÷ original × 100 for a positive nonzero original. Increase amount = original × rate ÷ 100.
A value rising from 80 to 100 increases by 20, which is 20 ÷ 80 × 100 = 25%. Increasing 80 by 25% also adds 20 and produces 100.
Calculations keep full internal precision and use controlled display precision with insignificant trailing zeros removed.
Two increase modes
Compare original and new values when both observed values are known.
Choose Increase a number by a percentage when the starting value and desired rate are known.
The second mode reports both the increase amount and new value.
Mode changes do not create alternate indexable URLs.
Zero, decreases, and negative baselines
Relative increase from an original value of zero is undefined because zero would be the denominator.
When the new value is lower than a positive original, the result is identified as a decrease and links lead to the focused decrease or change tools.
For a negative original, the tool shows the raw difference but does not label a conventional percentage increase.
Percentage Change documents an absolute-baseline convention for signed directional comparisons.
Interpreting the result
Keep units and comparison periods consistent.
A percentage increase is measured from the original, so reversing the inputs changes the base.
The calculator performs arithmetic only and does not infer whether an increase is desirable.
Methodology and limits
This deterministic browser-local tool strictly parses finite numbers and applies the formula stated above. It does not evaluate expressions, execute entered text, call a calculation API, or choose a contextual definition for you.